The open-loop system is unstable to the equilibrium (REF ). The Lyapunov feedback control proposed in [1]} can stabilize the linearized system without delay, and the Backstepping control designed in [2]} can stabilize the linearized system with input delay.
In the next section, we will design a RL-based controller under the states feedback and historical input feedback framework, where its control policy is trained by the PPO.
